Working on a 1955 evinrude 7518 7.5 hp. Problem when I screw down the retainging

Home Forum Ask A Member Working on a 1955 evinrude 7518 7.5 hp. Problem when I screw down the retainging

This topic contains 11 replies, has 5 voices, and was last updated by Avatar plymouth4 3 months, 1 week ago.

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  • Avatar
    plymouth4

    Replies: 6
    Topics: 3
    #176752

    When the retaining ring screws are tight I cannot turn the throttle shaft. Any help would be appreciated.
    Thanks plymouth 4. The retaining ring is flat side down, fits in the grove on top of the engine. When all four screws are tight I cannot turn the
    throttle shaft. Have checked the clearance on the screws and their is sufficient clearance. All holes in retaining ring line up with the mag. plate.
    When screws are loose the mag. plate will turn withe the throttle shaft. This baffle me.

    Thanks for any help. plymouth 4

    • This topic was modified 3 months, 1 week ago by Avatar plymouth4.
    olcah
    olcah
    US Member - 1 Year
    Replies: 325
    Topics: 69
    #176754

    Just guessing that you are referring to the 4 screws that hold the magneto plate down? In that case could the ring the screws go into be upside down? If you describe situation a bit more completely one of the fellows that know this engine well will come along and answer your question.

    frankr
    frankr
    US Member - 1 Year
    Replies: 4385
    Topics: 43
    #176756

    Did it work before you took it apart? Kind of sounds like somebody bent or dinged the brass magneto support ring in an effort to tighten up a wobbly magneto plate. You didn’t do that did you?

    bobw
    bobw
    US Member - 1 Year
    Replies: 601
    Topics: 28
    #176763

    Retaining ring should be flat side up. As Frank noted, the brass support ring may also be bent.

    Bob

    1954 Johnson CD-11
    1956 Johnson RD-18
    1958 Johnson QD-19
    1959 Johnson QD-20

    • This reply was modified 3 months, 1 week ago by bobw bobw.
    • This reply was modified 3 months, 1 week ago by bobw bobw.
    Avatar
    plymouth4

    Replies: 6
    Topics: 3
    #176781

    YES IT DID WORK. i HAD A WOBBLE IN IT AND TRIED TO STRAIGHTEN IT OUT. wILL CHECK IT OUT AGAIN. tHANKS FOR TH INFO. WILL KEEP POSTED ON PROGRESS.

    Avatar
    fleetwin
    US Member - 2 Years
    Replies: 2713
    Topics: 33
    #176788

    The aluminum threaded retaining ring should be installed with the flat side up…Did you replace the coils? If so, I have found that some of the OEM coil screws are just a bit too long and can bind the mage plate….
    What did you do to “tighten” the wobbly mag plate? “Dimpling” the brass retaining ring is a very delicate process…The mag plate will bind if you were too aggressive…

    Avatar
    plymouth4

    Replies: 6
    Topics: 3
    #176815

    Yes I did the wobble plate fix. probably was to aggressive. Will check and report back. Coils were replaced.
    Thanks for the info.

    Avatar
    plymouth4

    Replies: 6
    Topics: 3
    #177012

    Rechecked the support ring, straightened the support out and reinstalled, and it worked. But, still have the magneto plate wobble. Any suggestions?
    Thanks for all the info.
    Plymouth 4

    Avatar
    fleetwin
    US Member - 2 Years
    Replies: 2713
    Topics: 33
    #177045

    Well, you might look for another mag plate….But, keep in mind, that the boss on the crankcase might be worn also….Does it wobble up and down, or side to side, or both?

    Avatar
    plymouth4

    Replies: 6
    Topics: 3
    #177151

    Wobbles up and down and side to side. The boss on the crank case seems to fit snug.

    Avatar
    fleetwin
    US Member - 2 Years
    Replies: 2713
    Topics: 33
    #177154

    Are you sure you have the threaded aluminum retainer plate oriented correctly? Flat side should face up towards the mag plate….
    Up and down movement is controlled by the fit between the mag plate/brass ring retainer/aluminum threaded retainer.
    Side to side movement is controlled by the fit between the mag plate brass bushing and the crankcase boss it rides on…
    The threaded aluminum retainer has a “step” machined into it that helps control the up/down movement, the brass retainer ring is sandwiched between these two pieces. So, if the aluminum threaded retainer is damaged/worn or perhaps the threads/screws are messed up, there will be up/down movement. The brass retainer ring could be worn down, or perhaps the surface of the mag plate that rides on the brass retainer is worn….
    Tell us more about the history of this engine, is it new to you? If not, why is it that you are working on the ignition? Perhaps posting some pictures will help.

    “Dimpling” the brass retainer is a common “fix” for a sloppy mag plate, but you must be very careful to avoid the situation you described from occurring….

    Avatar
    plymouth4

    Replies: 6
    Topics: 3
    #177159

    Thanks again for the info. I finally got everything working again, what a process. I took the support plate out and hammered it back into place gently, reinstalled
    and still had some wobble. Took off the mag plate, dimpled the support plate reinstalled. It was tight again, problem solved. Set the points at 0.20, gapped the plugs.
    Hope to have it on the water in the next few weeks time permitting. The outboard was bought by my father back in 1955, coils, pts. cond, i replaced.
    Thanks again, appreciate all the help.
    Plymouth 4

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